Adjustable angle-square



(No Model.)

L. K. BARTLBY. ADJUSTABLE ANGLE SQUARE.

Patented Apr. 24, .1894.

- 1N VEA/T012 YN: NATIONAL uwoaRAPmNo COMPANY.

UNITED STATES- PATENT OFFICE.

LOUIS K. BARTLY, OF WINONA, MINNESOTA.

ADJUSTABLE ANG LE-SQ.UARE.

SPECIFICATION forming part of Letters Patent No.518,685, dated April 24, 1894.

Application met June 2o, 1893.

`To all whom it may concern.-

sota, have invented certain new and useful Imj provements in Adjustable Angle-Squares and I do declare the following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the figures of reference marked thereon, which form a part of this specification.

My invention relates to improvements in that class of instruments known as carpenters adjustable squares, which are designed for drawing or laying oft angles of diterent degrees.

The object of the invention is to provide an improved instrument ofthe above description which shall possess superior advantages with respect to simplicity, convenience and etliciency.

t The invention consistsin the novelconstruction and combination of parts hereinafter fully described and claimed.

In the accompanying draWings,-Figure 1 is a perspective view of an instrument constructed according to my invention, showing the ruling blades distended. Fig. 2 is a similar View showing the blades folded up. Fig. 3 is a central longitudinal section ot the same.

In the said drawings the reference numeral l, designates a square bar, having a horizontal slot 2, extending from one end to near the other end thereof. This bar on its top and bottom is formed with a slot 3. The end of the bar, `at 4, is provided with a pivot pin 5, on which is pivoted two ruling blades 6, made of metal,or other suitable material, and which are capable of being distended, as seen inFig. 1, when in use, or ot' being contracted and folded in the slot 2, when not in use, as seen in Fig. 2. The free ends of these blades are formed with nicks 7, and the bar 1 with recesses 8., Pivoted to these blades intermediate their ends are connecting bars 9, pivoted at their opposite ends, to ascrew bolt 10, provided with athumb nut 12. This bolt is provided with a head 13, and passes through two rectangular plates 14, and also through the Serial No. l179,113. (No model.)

slots 8. These plates are slidable on the top and bottom sides of bar 1, and they are connected together by a guide blockl5, secured thereto which is slidable in said slots 3.

On its upper side the bar 1, which in some cases may serve as a straight edge, is provided with a number of graduations 16, marked with suitable characters which designate the angle of the blades with respect to each other or to the bar.

The operation will be readily understood. When the device is not in use the blades are folded up so as to lie in the slot 1, by which they are protected from injury. When in use, the thumb nut 12 is loosened, and the blades are partly drawn out bythe finger nail engaging with the nicks in the free ends thereof. The plates 14 are then slid toward the end of the bar distending the same until the desired angle is attained which will be indicated by the end of the upper plate registering with the graduating mark on the bar determining said angle.

From the above it will be seen that I provide a very efficient instrument, by which angles of different degrees may be marked or laid oft, and which when not in use can be folded into a compact space fortransportation.

By means of the guide block an extended Vbearing is formed for the sliding plates, thus preventing twisting of the blades in their movements. j

Having thus described my invention, what I claim is- In an adjustable square, the combination with the square bar havin-g slots in its sides and top and bottom, and graduating marks and characters on its top, of the pivoted marking or ruling blades, the connecting bars pivoted thereto, the headed screw bolt, having a thumb nut, passing through the top and bottom slots of said bar, the slidable plates, through which said bolt passes, the guide block secured to said plates and passing through said slots, substantially as described.

In testimonywhereof I affix my signature in presence of two witnesses.

LOUIS K. BARTLEY.

Witnesses:

W. A. FINKELNBURG, EDWARD LEES. 

